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Thursday, July 15, 2010

Ever since Sony introduced its high-end PCM-D1 — the fit-in-your-hand 24/96 recorder — in 2005, I have been enamored with these self-contained, battery powered marvels — with built-in microphones and solid-state drives. Designing them with efficient battery options, good mics, and ample recording memory, these devices are well-suited for numerous uses — audiophile, professional, broadcast and musician. And they now come in all sizes and price ranges, from a couple of grand to a couple of hundred bucks.

I had an inkling the DR-100 would be at or near the top of its class since TASCAM, TEAC’s professional division, produces some of the best audio recorders in the world. I happen to own the mid-sized AC/DC-powered HDP2 Compact Flash 24/192 recorder and the high-end pro/audiophile DVRA-1000 that records and plays both high-res PCM and DSD.

Features

Retail priced at $599, but selling just north of $300 via Internet order, the TASCAM DR-100, records up to 24-bit/96kHz and comes standard with built-in cardioid and omni-microphones. It also includes such niceties as dual-battery power, infrared/wired remote control, balanced XLR and mini-jack line I/Os. It even has a monitor speaker so you can check whether you recorded correctly.

The DR-100 is larger than many of the latest crop of handhelds, such as Sony’s PCM-M10, M-Audio MicroTrack, and Yamaha’s ultra-small PocketTrack series. But the TASCAM’s feature set needs a bit more space — since it has two battery compartments and bottom-mounted XLRs.

On the DR-100’s front panel are numerous controls and the informative LCD screen. The buttons including Home (takes you to the main screen) Menu, Playback Control, I/O Loop, Quick (easy delete or tagging of tracks) Forward, Backward, Stop, Play/Pause, Record and Auto Record. A Jog-Wheel/Function button setup allows shuttling through Menu items, and a four-position Input selector slide-switch activates either the line, built-in omni mics, cardioid mics, or external XLR microphone inputs. The microphones are on the front of the unit.

The front panel also contains the Charge LED and Peak recording-over indicator; a small monitor speaker is nestled in between the omni mics and just underneath the cardioid microphones.

The back panel includes slide switches for Mic Gain (Low, Medium and High), Limiter switch, 48-volt phantom power, and speaker On/Off. The left side of DR-100 contains a USB input for computer connection, AC adaptor plug for charging the batteries, power button, rotary volume control, and separate 1/8th-inch stereo headphone and line outputs. An 1/8th-inch stereo line input is also included.

The TASCAM’s audio performance, ergonomics, features and ease of use is first rate. It has really good cardioid microphones and the A/D-D/A converters nicely capture a recording in all its 24-bit detail.

As full featured as it is, the DR-100 does not have a digital input or output port of any kind; I would like to see it have at least a digital output for feeding an external DAC. The DR-100’s right-hand side panel includes concentric L-R gain controls and the lithium battery compartment. The AA x 2 battery compartment (disposable alkalines or nickel metal) is on the back. You can set up the Battery Management menu to select battery priority — Main and Backup. The options are: 3.7V lithium as Main; 3V AA pair as Main. When the Main battery runs down, the other takes over as Back Up. The two battery setup allows long-bouts of recording and playback, plus enables battery swaps — without shutting off the unit. The user can continue the recording or listening session while changing the batteries!

The handheld DR-100 can be placed with precision, thanks to the handy mic stand/tripod mount on the back panel; the wired/wireless remote control also enhances the recording flexibility with Record, Play, Stop, Forward, and Back functions. You can’t, however, set the level with the remote.

Although there are numerous operation options, the DR-100 is quite easy to use, and manual point and record takes just a few set-up steps. However, if you want to dig deeper into the DR-100, here are a number of features that may be of interest:

•Auto Record and Stop — Set up the machine to start recording when a certain level threshold is exceeded. Same principle allows the DR-100 to stop recording when a defined minimum level is set.

•Overdubbing — You can actually add a track to your already recorded stereo track by simply recording the new track onto the existing track. (This feature does not operate at 96 kHz).

The Mix Balance menu item allows the level of the existing track to be adjusted versus the overdub level — in order to produce a main track with equal levels.

•PreRecord — Allows the DR-100 to record two seconds of sound before recording is activated. •Record Delay — Delays the record activation for two seconds to lessen the chance of recording handling noise when pushing the record button.

The DR-100 records audio onto removable SD (up to 2GB) and SDHC cards (up to 32GB). A track’s maximum file size (adjusted in the Setup menu) is 2GB. When recording, a track that exceeds 2GB will automatically start another track.Internally, the DR-100 is designed with high-quality AKM converters. The low-noise mic preamps are also quite good, though you won’t get a lot of extra gain out of them.

The DR-100 is very easy to use and operates like an analog tape recorder (huh, what’s an analog recorder?). If you go through the menus, you can set it up and record and play — without reading the manual. You can easily set the word length, sample rate, create custom playlists to place your tracks, and there are handy track options, such as Quick Delete, ID Tag and Track divide.

The DR-100 records audio onto removable SD (up to 2GB) and SDHC cards (up to 32GB). A track’s maximum file size (adjusted in the Setup menu) is 2GB. When recording, a track that exceeds 2GB will automatically start another track.

These handheld recorders can be used for numerous recording/playback tasks. I like to use them to record acoustic and electric guitar, — sometimes with the internal mics, and sometimes with professional mics through the XLRs. Other times, I’ll use a recorder to make quick, high-res music dubs from 24-bit or DSD players when I am too lazy to set up the big recorder. Take an analog line-out from a high-res DVD-A or SACD player, hook up a good cable to the recorder, and, voila, I am rewarded with an excellent PCM copy of a high-res recording.

I also use my Flash-drive marvels as a high-res “iPod’’ style player for 24-bit music playback. I copy music from DVD-As, SACDS, online downloads, tag the track title with .wav, and drag them back to the recorder. I grab a pair of good headphones and listen to the high-resolution, PCM-ized tracks at 24/96 — anywhere I please.

The setup

I first set up the DR-100 to record my Martin Custom OO-28V fingerstyle guitar — a 12-fret, red spruce top and Indian Rosewood, small body acoustic guitar that I commissioned Martin to build for me in 2005. It has a wonderfully warm, yet percussive, top end that sounds great when recorded. I have recorded it with oodles of mics in high-resolution PCM (and DSD) and know the sound intimately.

In my second test scenario, I recorded the guitar with external phantom-powered mics; I chose the Audio-Technica 4051B instrument microphones that I reviewed last year in my mic round up. I also recorded a Martin HD-28V, a big sounding dreadnaught with the same setup.

Following the guitar recordings, I dubbed numerous DVD-As and SACDS from an Oppo BD-83SE (internal converters and the analog output of a connected Benchmark DAC1 Pre). The recorded tracks were loaded into the Macbook Pro via the USB link, and burned as DVD-As using Minnetonka DiscWelder Bronze. The dubbed tracks were then played through the Oppo’s internal converters and the external Benchmark D/A. This allowed me to hear the accuracy of the A/D converter.

First up, I recorded A/D several DVD-As and SACDS through the DR-100’s dedicated line input. Through the output of the Oppo BDP-83SE (and later the Benchmark DAC1 Pre), I connected a Wireworld RCA-to-min-jack cable to the DR-100's line input. My first recording was from the Natalie Merchant — Tiger-Lily DVD-A. Setting the DR-100 to 24 bit/96 kHz, I recorded the cut "Carnival," the album’s key single — with its modern rock/alternative electric guitar/vocal oriented vibe. The song also has great separation in the percussion transients.

On the DR-100 playback of the dubbed track, using the Shure SRH-880 headphones, I was impressed with the TASCAM’s playback quality. The drum cymbals had nearly the same open character and separation as the song played through my high-end separates. Pretty good sounding headphone amp, as well, with plenty of gain to drive the AKG K701s.

To check the A/D’s accuracy, I downloaded the track to the Macbook Pro, burned a DVD-A in Bronze and played it back via the Oppo and Benchmark combo. I was impressed. Yes sir, folks. For $300+,the TASCAM’s A/D is quite good; it is audiophile good! I did the dub-and-transfer-to-Mac routine for a number of recordings, and was never disappointed with the DR-100’s A/D sound quality. It puts many of the big pro converters from the 1990s to shame.

On the DR-100 playback of the dubbed track, using the Shure SRH-880 headphones, I was impressed with the TASCAM’s playback quality. The drum cymbals had nearly the same open character and separation as the song played through my high-end separates. Pretty good sounding headphone amp, as well, with plenty of gain to drive the AKG K701s.

Of course, since the DR-100 is loaded for live recording, I made a number of guitar recordings with the built-in cardioid microphones. I recorded the 00-28V custom Martin via the DR-100, mounted on a tripod. I played mostly fingerstyle music and located the DR-100 about 15-inches from the guitar.

After recording, I listened to the playback of the cardioid mic recordings through the TASCAM — using either the Shure or AKG cans. The listening session revealed that these mics sound really good — containing no high-end harshness that I have heard on other small, self-contained PCM recorders. Much of the fingerpicked overtones and detailed presence of string attack were captured by the DR-100 mics/converter. Although the DR-100‘s headphone output is not quite as spacious as my $2,000 Sony PCM-D1’s headphone amp, the TASCAM’s playback is noticeably smoother on music with abundant treble. With converters that date back to the early 2000s, the PCM-D1 is starting to show its age.

I also recorded a larger Martin dreadnaught and a Gibson SJ-200 with the internal cardioid microphones. Again, the recording was of very high quality DR-100 any proximity effect that can make a large guitar sound boomy. For a point-and-record high-resolution handheld, this is one of the best that I have heard for recording acoustic guitar. The combination of its A/D and microphones brings out the detail from bottom to top — and really good imaging. After copying these big guitar recordings to a DVD-A and playing them through the Oppo/Benchmark DAC1 Pre, I again confirmed my initial impressions of the high-quality A/D.

If you want to go beyond the internal cardioid microphones, the DR-100’s XLR input and internal phantom power allow the use of separate professional condenser microphones — which can give you ultimate recording quality. The DR-100 and the pair of A-T 4041B instrument mics captured the big sound of the Martin HD28V dreadnaught — characterized by its prominent bass and crisp presence. Through the unit’s internal DAC/headphone amp and played through high-end separates, the playback of the A-T mic’d HD-28V recordings, again, showcased the recorder/mic combo’s ability to soak up all the guitar detail in glorious 24-bit.

Dynamic microphones matched up well with the DR-100, though I had to run the gain near its maximum with my Audix I-5s. The preamps have sufficient gain, but not a lot extra.

As I pointed out in the Features section, the DR-100 also has two built-in omni mics, but they are for general recording purposes and have quite a bit of noise when levels are increased. When using the omni microphones, I discovered the DR-100’s only significant negative — its internal speaker noise bleeds into the mics when recording. The internal speaker is positioned between the omni mics (and a couple of inches behind the cardioid mic). This design allows the omnis to easily pick up the speaker amplifier’s low-level, but noticeable, “ hiss” noise.

The combination of its A/D and microphones brings out the detail from bottom to top — and really good imaging. After copying these big guitar recordings to a DVD-A and playing them through the Oppo/Benchmark DAC1 Pre, I again confirmed my initial impressions of the high-quality A/D.

According to TASCAM, the speaker was added to the DR-100 so recordists could immediately check their work — bypassing the headphone routine. However, even with the Speaker On/Off switch in the “off” position, the DR-100’s amp circuit is still active, and some hiss always emanates from the speaker. The omni mics close-proximity to the speaker easily picks up the noise.

I talked to TASCAM about the noise; they confirmed that their sample also had hiss through the speaker, so it must be a side effect of the design. To reduce the noise when recording with the omnis, I experimented with covering up the speaker with duct tape, a piece of rubber, etc. The noise can also be heard with the cardioids when recording a quiet room, but just barely. But with music, even gentle guitar picking, I could not hear the noise with the cardioids.

In my opinion, adding the speaker to a small recorder is unnecessary. It forces the manufacturer to make design compromises, including finding a place to put it and extra power consumption. Since the headphone jack is available for the end-user to monitor and review the recording, why not just get rid of the speaker. That’s what the headphones are for. The original small high-res handheld, such as the M-Audio MicroTrack and Sony PCM-D1 did not have speakers, but I see the new trend of small recorders now being equipped with the speaker. (The newer, lower-cost, Sony PCM-M10 contains a speaker, but it is on the other end of the unit, away from the built-in microphones).

My other caveat, with regard to the DR-100, is using it to record while holding it in your hand. Depending on how firm you hold it, there can be handling noise. If you want to record a high-quality interview or other sound, it is better to mount it on a tripod or use a separate mic that is better suited for handling while recording.

Speaking of tripods and stands, the DR-100’s remote is a handy device to allow you to place the recorder and activate its recording functions from a distance — just like a recording engineer. Since it does not allow the operator to set the gain remotely, you must do your initial setup at the unit, then position yourself with the remote so you can activate the recording. It worked fine, with or without the hard-wired 12 ft. cord.

Battery life is important when using a handheld recorder, and the TASCAM’s dual-battery configuration gives extended recording and playback time with fresh batteries. When the DR-100‘s lithium battery was new, I got as much as nine hours of playback at 24-bit — with it and the new AA alkalines operating in tandem. A fresh lithium will net about five to six or hours of playback by itself. A fresh pair of alkaline AA pair lasts as long as three hours with normal continual playback. More record-intensive tasks will, of course, lessen battery time.

I did notice that the lithium’s lifespan reduced considerably with frequent usage. Under normal use, my lithium battery life was down 75 percent at eight months. And the lithium battery is not cheap at $35-$40. (I found one for $34 on Amazon). It’s best to keep fresh/charged batteries in the unit if you want to operate free of the AC adaptor tether.

BTW, the included AC adaptor unit (or USB computer connection) will only charge the lithium battery, not the AAs — even if you use nickel metal rechargeables. Also, I found that the 5V low-current USB connection gives a more complete charge than the high-current AC adapter.

My wish list for the next version of the DR-100? Get rid of the speaker, or eliminate its low-level noise. And I would like to see digital I/O, or at least a digital output. The competition, such as the Sony PCM-D50 and the M-Audio MicroTrack already have such connections. It is nice to be able to hook up a high-end converter to these small recorder/players. For example, it can made a nice high-end, space-saving audio player setup when combined with a Benchmark DAC1 Pre.

The verdict

The TASCAM’s audio performance, ergonomics, features and ease of use is first rate. It has really good cardioid microphones and the A/D-D/A converters nicely capture a recording in all its 24-bit detail. Ignoring the omni microphones and built-in speaker, it merits a Stellar Sound Award. I was so impressed with the recording quality that I bought one.

Editor's Note: Thomas E. (Tom) Mintner has joined the Everything Audio Network with his test and measurement services, SpecCheck by Audio Support Northwest. A SpecCheck evaluation utilizes the extensive hardware and software test resources available at his lab, co-located near Portland, Oregon with his other company, NTI Americas Inc. NTI Americas is part of the worldwide NTi Audio partnership, which manufactures audio analyzers/generators, as well as PureSound production test solutions for factory production lines.

Although portable digital recorders and other small audio devices face a number of challenges at the design level, the TASCAM DR-100’s test results show a very clean recording capability. Technical challenges for this class of recorder/player are created because of limits on battery power consumption — as well as the related heat dissipation, PC board space, and other product package-size and functional issues.

For example, A/D and D/A converter chips often selected for use in mains-powered studio grade converter products, are generally too large and consume too much power, often at internal supply voltages not available in a mobile device. Sometimes, various combinations of switching-power supply and audio-path technologies for mobile devices combine in ways that can provide a fairly good numerical spec — but with “digital nasties” visible down near and above the average noise floor in a spectrum analysis of the signals.

It seems that the engineers at TASCAM took on these challenges and produced a design with not only excellent numerical specifications — but also clean, uniform noise floors and residual distortion characteristics.

The following commentary summarizes my findings during testing of the DR-100. I tested both the DR-100’s line inputs, which are on 1/8-inch (aka 3.5-mm) stereo phone jacks, and via the XLR connectors intended for external microphones.

Interestingly, the different audio paths measured nearly identical (once input levels and gains were figured in), except when the highest overall gain settings were used. The good results from either input is significant because I have seen some small recorders that don’t measure up when an external microphone is plugged into the microphone inputs, or when you need a little more gain. With critical use likely to come through external mics, the graphs represented in this bench test were obtained via the DR-100’s XLR connectors.

Given the positioning of this product, I felt that end-users would buy it more for its linear recording modes, and so I focused my measurements within those parameters. Starting with the basics, the DR-100‘s frequency response,I took readings at the three sampling rates 44.1 kHz, 48 kHz and 96 kHz (Figure 1); the measurement graphs were scaled to illustrate the well-behaved HF roll off tails as the signals approach the frequency limits of each rate.

To better judge the response “flatness” and response matching between channels, Figure 2 shows the response within only a 20 kHz range and with a greatly expanded vertical scale. Also the second channel was deliberately offset manually to allow an easier “eyeball” comparison of the uniformity of response between the two channels.

The other important area to note is the relatively low deviations or response ripple towards the top end — where the system would begin to naturally roll off. Of course at each higher sample rate (48 kHz or 96 kHz), the response extends much farther beyond 20 kHz, as shown in Figure 3.

Figures 4 and 5 show the results of two less-conventional tests. Figure 4 is a spectrum analysis of the residual noise and distortion left when a high-level standard single tone signal is recorded on the DR-100 — with the original signal fundamental removed prior to the FFT analysis. This measurement was then repeated and averaged, which makes coherent discrete signals emerge visually on the graph and lowers the relative visual level of any regular noise, which is non-coherent.

Aside from some expected harmonic distortion at very reasonable levels the only other noticeable artifacts I could see were a bit of power line harmonics. Since I was running the DR-100 on its included external AC-to-DC supply, these hum components could have been related to the wall power.

A second test was run using a synchronous multi-tone of very wide bandwidth and high level. Sine testing and standard THD+N measurements always provide some useful and irreplaceable reference comparison points for almost any audio testing. But we all know that music does not usually consist only (with homage paid to David Tudor and John Cage) of single pure sine waves. Multi-tones are somewhat more music-like collections of sine waves — with known phase, amplitude and frequency characteristics. These test signals are chosen so that the entire signal may be presented at a level that is tolerable to a device under test — without causing clipping or overload due to crest factor.

In essence, multi-tone signals are a form of wide-band “stress test” for an audio device. Figure 5 shows the DR-100 with a wideband, equal amplitude, multi-tone test signal. Such a signal is not bandwidth-shaped like a true music simulation would be, but provides a difficult test for any digital device that might exhibit non-linearity with complex input signals. The comb-like trace is the multi-tone signal itself.

With digital audio devices, I am interested in the “cleanliness” of spaces in-between the “tines” of the comb. The stuff spaced down in between the many multi-tone components is where noise, distortion, and, in particular, any “birdies” or other digital-related “trash” would appear.

Try this test on a device using any of the popular reduced bit rate codecs, and the bin spaces between the tones fill gradually with audio “debris.” However, the importance and audibility of that debris is then subject to mitigation due to the masking phenomenon, such that much of it is inaudible in the presence of the nearby program frequencies. With its linear recording design, it is comforting that we don’t have to worry about the reduced-bit audio debris clutter in the DR-100‘s measurements.

I also ran a standard signal-to-noise test on the DR-100, and the result as expected varied slightly — depending upon what maximum reference level is input to the device; which device input is used; and the gain setting. But the average signal-to noise ratio was always better than 90 dB, typically 93 to 99 dB.I also made a sweep, measuring THD+N at many frequency points, within a 22 kHz measuring bandwidth. The extremely respectable noise distortion performance of the DR-100 can be seen in Figure 6.

Since this is still primarily a field recorder, it offers selectable stages of low-frequency roll-off filtering for recording. These High Pass (HP) filters could be used for either speech-only recordings, or even for music recording in a venue with, say, typical HVAC low-frequency room rumble. Figure 7 shows the low-frequency response of the DR-100 for each of the available low-cut filters.

Tom Mintner’s career/professional training spans both music and audio engineering, starting with his first professional experience when conductor Henry Mazer first tapped him as a substitute orchestral clarinetist at the age of 16. His formal training at Northwestern University included both Music and Physics and his informal training included jazz, electronic music and commercial recording work in nearby Chicago. He then was appointed a Rockefeller Foundation sponsored Performer/Fellow and Audio Specialist in the Center for New Performing Arts at The University of Iowa.

Joining Rupert Neve Inc., He began a 30+ year career directly in the professional audio equipment sector. Working in New York and then Nashville with Neve and then Studer ReVox, he has held a variety of senior level technical, sales and management positions. Before founding NTI Americas he was a long-time key employee and part owner of audio test & measurement company Audio Precision. He also developed semi-conductor ATE instruments for Credence Systems. He is a voting member of NARAS, and a member of the Audio Engineering Society, the Acoustical Society of America and IEEE.